FACETIME- Suicidal cells: UVA's Petri dishes on a bad bug

Non-scientists probably never stop to analyze how our bodies grow from six or eight-pound infants at birth to mature adults of considerably larger bulk. One way is that cells have a built-in mechanism that tells them when to kill themselves so new cells can take their place.

Dr. William Petri (no relation to the dish) has used this fact of physiology to unlock the secret of a disease that affects more than a billion people, mostly in developing countries where access to clean water is limited. Along with UVA assistant professor Eric Houptand scientists at Techlab, a Blacksburg research firm, Petri, chair of UVA's division of infectious diseases, has been awarded a five-year $4.2 million grant from the National Institutes of Health to develop a vaccine against amebiasis, caused by a parasite in dirty food and water.

"We're working together to test in a mouse model vaccines against the disease," Petri says. "Histolytica penetrates the bowel wall and destroys tissues, causing diarrhea and dysentery. We've spent a lot of time over the last 15 years trying to identify the process by which the parasite kills the cells." What they've determined is that it tricks cells into self-destructing by activating the mechanism by which they commit suicide.

Petri, 50, explains, "Our vaccine is designed to create antibodies against the programed cell death. We now have a prototype vaccine that provides protection in an animal model, but we're five years away from having a human trial."

How does one decide to spend energy fighting a tiny parasite that for years did not create much buzz? "I've always had an interest in infectious diseases," Petri says. "Tropical diseases are interesting to me because they affect so many milions of children, but there are not many people working on them because they don't affect people in the U.S."

Long-time colleague Barbara Mann came from the University of Wisconsin to join Petri in this research. "Because Dr. Petri isolated the protein that allows the parasite to attach itself to the cell, he can make antibodies against it," she says. She adds that Petri started a study with a group of children in Bangladesh because in addition to gastrointestinal problems, the parasite may cause cognitive and developmental defects in youngsters.

"This work can have a significant impact on childhood health, especially in developing countries" Mann says. "Dr. Petri is someone who can take a project from the lab to practical use. He's taken some basic discoveries from 'bench to bedside.'"

Mann is also quick to praise Petri's impact on colleagues. "He's fun to work with and not stuffy. He's been a great role model for younger scientists in the lab," she says.

And as for the inevitable question, no, he's not related to Julius Richard Petri, the German bacteriologist who invented the dish that bears his name. "Our family is from Alsace Lorraine, which is where Dr. Petri of the petri dish is from. But we don't thnk there's any connection," the local doc dishes.